Small VSI

[Skippydiesel]

New aircraft all "lectricary" so I think I would like to have a back up air speed indicator.

To fit diminutive size of aircraft and panel, would like to go for about a 50mm (or smaller). Again I would like the benefit of your learned experience & observations.

Make?
Model?
General comments in support/against a particular Brand/Model?

Sonex claimed airspeed range 35 knots to Vne 170 knots - I have always understood instruments of this kind are most accurate in their mid indicating range - Is this peoples experience/understanding ? If so, I guess I am looking at an ASI that indicates from about 20 knots - 200 knots - your comments?

[N43WX]

MGL has instruments that work well. Can't vouch for the Sonex as I'm still building but I've used them in an RV with good success.

[DCASonex]

For best accuracy at low air speeds, consider adding a lift reserve indicator. No electric required.

David A.

[Scott Todd]

Do you have any time in a Sonex? Its a pretty honest airplane. I do lots of flight reviews and transition training in various airplanes and have about 20 hours giving instruction in Sonex's. Did you mean ASI in the title?

I want the Pilot to be familiar with the attitude of the airplane vs airspeed. So after a little practice, one of my things it to block the airspeed from their view and do a few simulated engine outs. The lesson is usually stall/spin avoidance but I always toss in airspeed indicator failure as a talking point. They quickly adapt to the nose position of the airplane and don't have any problem landing that way. They tend to come in a little fast and float a little but if the emergency is the ASI quit, it doesn't matter since you probably wouldn't pick a short field for that situation.

[daleandee]

For best accuracy at low air speeds, consider adding a lift reserve indicator. No electric required.

David A.

I agree with David. I installed a mechanical LRI (Lift Reserve Indicator) on my previous Sonex and also in my current Cleanex. I tend to use them more than the ASI for take-off and landings.

[Skippydiesel]

Dyslexia Ruled KO !

Yes I should have put ASI

[Skippydiesel]

Do you have any time in a Sonex? Its a pretty honest airplane. I do lots of flight reviews and transition training in various airplanes and have about 20 hours giving instruction in Sonex's. Did you mean ASI in the title?

I want the Pilot to be familiar with the attitude of the airplane vs airspeed. So after a little practice, one of my things it to block the airspeed from their view and do a few simulated engine outs. The lesson is usually stall/spin avoidance but I always toss in airspeed indicator failure as a talking point. They quickly adapt to the nose position of the airplane and don't have any problem landing that way. They tend to come in a little fast and float a little but if the emergency is the ASI quit, it doesn't matter since you probably wouldn't pick a short field for that situation.

Its a nice idea - flying by attitude/power and certainly works in practice drills, however I have always been a believer in having a reasonable degree of redundancy. Taking your argument one step further - no need for a stall warning and my current aircraft doesnt have one BUT at a small extra cost a stall warning or A of A can be fitted which may just save your bacon some day. In the unlikely event of the Dynon going out on strike (completely blank panel) having a basic ASI and compass will definitely get me home without any difficulty.

[Skippydiesel]

For best accuracy at low air speeds, consider adding a lift reserve indicator. No electric required.

David A.

I agree with David. I installed a mechanical LRI (Lift Reserve Indicator) on my previous Sonex and also in my current Cleanex. I tend to use them more than the ASI for take-off and landings.

Hi David - until your comment, I hade never heard of this device - gets a good write up in Kitfox - did you purchase or make yours?

[Sonex1517]

I have a UMA round gauge ASI and Altimeter and like them. The ASI is more accurate (in my installation) at cruise by about 7 mph compared to my GRT Mini EFIS.

I also have an LRI and a TinyTach on the instrument panel where ai can look out the windshield on final and see power and lift remaining. It works well for me.

[Sonex1517]

If you want to build the LRI try this:

https://img1.wsimg.com/blobby/go/e83c7c ... 4222140376